Proliferation of communication technology enables multiple devices to communicate with each other. For example, two computing devices exchange content data (e.g., text, image, video, etc.). In one approach, content data is exchanged in an encoded format to improve bandwidth. For example, a transmitter encodes content data according to a pulse amplitude modulation (PAM) protocol and transmits the encoded data. A PAM protocol represents a value of data according to amplitude of a pulse. For example, amplitude of 100 mV of a pulse indicates a logic value ‘0’, amplitude of 200 mV of a pulse indicates a logic value ‘1’, amplitude of 300 mV of a pulse indicates a logic value ‘2’, and amplitude of 400 mV of a pulse indicates a logic value ‘3’. Accordingly, a single pulse can convey multiple bits of information, thereby improving a communication bandwidth.
Communication through a PAM protocol presents difficulties to a receiver design. For example, a receiver detects amplitude of a pulse from data received, and decodes the received data to obtain content data. Sensing amplitude of high speed data (e.g., over 50 Gbps) and decoding data according to the sensed amplitude involve a complex and challenging process. For example, a signal received by the receiver is subject to a distortion because of inter symbol interference (ISI). Specifically, energy in a symbol of a signal is spread over to the adjacent symbol. In some implementation, the receiver includes circuitries to compensate for such distortion. However, the circuitries to compensate for the distortion due to ISI degrade the receiver performance (e.g., speed) and consume additional hardware resources.
The details of various embodiments of the methods and systems are set forth in the accompanying drawings and the description below.